The invention relates to a modular inhalation tower for laboratory animals comprising two concentric vertical ducts around the vertical axis of the tower, which has a number of tiers, each of which comprises a tray for supporting individual inhalation chambers and radial connecting ducts, grouped in tiers and distributed at equal angles on each tier, in order to connect each inhalation chamber to the central internal distribution duct, the central external duct for evacuating the inhaled gas is formed with openings concentric with each connecting duct in order to connect each inhalation chamber with the central external evacuation duct.
The aim of these towers, in which animals are imprisoned in individual chambers, is to limit the distribution of aerosol to the respiratory tracts and to distribute a measured quantity of aerosol to the lungs. Inhalation devices based on this principle are described in an article by W.C. Cannon, E.F. Blantore and K.E. McDonald of Pacific Northwest Laboratories of Battelle Memorial Institute, in American Industrial Hygiene Association Journal, Volume 44, pages 923-928 (December 1983).
In the inhalation device described in this article, the aerosol is continuously distributed through a small tube to the nose of each animal and is inhaled on leaving the tube without being in contact with other parts of the animal's body or with other animals. Construction of a modular inhalation tower comprising a supporting tray at each tier was proposed in a technical memorandum published in Spring 1986 by the Geneva Research Centre of Battelle Memorial Institute.